Unless a community already has experience with volcanic ashfall, local governments and public organizations are typically not prepared for a rain of gritty ash. After having dealt with the ashfall from the 1980 eruption of Mt. St. Helens, communities in Washington and Oregon clearly recognized the need for local emergency plans and emergency public information plans for future ashfalls from Mt. St. Helens or other nearby volcanoes (FEMA, 1984). According to their experience, such a plan does not have to specifically deal with volcanoes, but can be written to deal with a wide variety of natural emergencies.
Removal and disposal of ash are probably the biggest challenges for cities and communities that may experience ashfall. Volcanic ash needs to be removed from urban areas even after a fall of only a few millimeters, and notification of an impending ashfall may allow for less than an hour of final preparation if such a notification comes at all. A number of factors will influence the removal methods employed, the ease with which ash can be removed, and the cost of any cleanup operation. These include ash thickness and grain-size and the availability of equipment. Removal of ash from roads was undertaken by a number of public works departments after the 1980 Mt. St. Helens eruption. Few, if any, of these organizations had developed plans for ash-removal prior to the cataclysmic eruption even after two months of significant activity at the volcano. Furthermore, little knowledge was available on how to undertake such a massive cleanup.
Dealing with ashfall effectively in communities requires careful planning and coordination among public agencies, businesses, landowners, and the public both in areas affected by ashfall and beyond. Many of the planning measures identified for businesses can be adopted for community and public facilities, including hospitals, buildings, power stations and equipment, and water-supply and waste-water treatment facilities.